1. Field of the Invention
This invention relates to an outboard motor.
2. Description of the Related Art
In outboard motors, manipulation of a throttle lever installed at a hull (boat) on which outboard motor is mounted, is usually transmitted to a throttle valve in an internal combustion engine (equipped in the outboard motor) through a cable to move the same to regulate the amount of air to be sucked into the engine.
When the throttle valve is operated manually through the cable, since the operator tends to have an unpleasant operation “feel” owing to, for instance, heavy load, an actuator has often been installed at the hull, that is connected to the engine throttle valve through the cable to power-assist the driving of the throttle valve. The add-on system using such an actuator has disadvantage that it takes up space at the hull for installing the actuator.
Attempts have been made to overcome the drawback. Japanese Laid-Open Patent Application No. Hei 2(1990)-279495 ('495), for example, teaches installing an actuator inside an engine cover at a position remote from the throttle valve (carburetor) in such a manner that the actuator is connected to the throttle valve through a link mechanism. However, this arrangement is disadvantageous in that its structure is complicated, that it adds to the number and weight of the components, and it needs a space for the link mechanism inside the engine cover. Moreover, since the prior art actuator is positioned inside the engine cover to be extended from the middle or center to the rear (i.e., the side opposite to the hull), maintenance operation from the hull is not satisfactory.